Audi A1 Cruise Control Failure: Electronic System Fix

I had a very similar issue with my 2013 Audi A3 last year. I have some experience working on car electronics, though I typically leave complex issues to professionals. The symptoms sound exactly like what I encountered, cruise control failure and error codes. After checking the fuse box myself, I took it to a workshop where they found the root cause was a damaged wiring harness connector near the throttle body. The wire insulation had worn through, causing intermittent connection issues with the electronic control system. The fix involved replacing the damaged cable section and properly securing the connector. Total cost was 95 Euro for parts and labor. Since the repair, the steering wheel controls and cruise control have worked flawlessly. To better assist with your specific case, could you share: Are there any other electronic functions affected? What exact error codes are showing in diagnostics? Does the issue occur more frequently when the engine is cold or warm? Have you noticed any correlation with weather conditions? These details would help determine if your A1 is experiencing the same connection issue I had or if it might be related to another component in the electronic control system.

Thanks for sharing your experience. My latest service was just 2 weeks ago at 44106 KM. After running additional diagnostics yesterday, I noticed the malfunction also affects other steering wheel controls intermittently. The error codes point to communication issues in the electronic control unit. The problem occurs regardless of engine temperature or weather conditions. The service technician suggested it could be related to the throttle body actuator, but wanted to perform more thorough testing before confirming. Given the persistence of these electronic issues despite the recent service, I will probably need to schedule another workshop visit for a complete system check.

Thanks for the update on your A1. Given the similarity to my A3 case, I think we are dealing with more than just a throttle body actuator issue. The fact that multiple steering wheel controls are affected intermittently strongly suggests a wiring or connection problem in the electronic control system. When my A3 showed these symptoms, the initial diagnosis also pointed to the actuator. However, the widespread electronic malfunctions were actually stemming from damaged wiring affecting multiple systems. The communication errors you are seeing support this theory. Since your issue persists regardless of conditions and affects multiple controls, I would recommend having the workshop specifically check: The main wiring harness connections, The electronic control unit grounds, The steering wheel control module, The CAN bus system integrity The non-functional cruise control might just be a symptom rather than the core issue. In my case, fixing the wiring resolved all the electronic glitches at once. Would you mind sharing the specific error codes? This could help confirm if your issue matches the pattern I experienced with my A3.

Thanks for providing such detailed information about your experience. Your suggestion about the wiring harness being the potential culprit makes a lot of sense, especially given how the malfunction affects multiple systems. The error codes I am getting are P0638 and U0121. These communication-related codes seem to align with your theory about wiring issues rather than just a faulty throttle body actuator. After checking my service records, I found the steering wheel control module was actually flagged for inspection during my last service, but no issues were detected then. I will schedule another workshop visit next week and specifically request they inspect all the points you mentioned, particularly the wiring harness connections and CAN bus system. The intermittent nature of these electronic issues certainly suggests a connection problem rather than a complete component failure. The fact that your repair was relatively straightforward and cost-effective gives me hope this wont require replacing major components. Will update once the diagnostics are complete and they identify the root cause of these electronic glitches.